Concrete
Concrete is a building material. It is not often used for the main living space. Generally, it's used for exterior spaces such as driveways or garage floors. The real estate agent I worked with when buying a house told me of an old saying about concrete, "There're two kinds of concrete. The kind that's cracked, and the kind that's going to crack." Concrete is made up of Portland cement, sand and gravel. Stamped concrete can be designed to look like different materials or have various appearances, and has become increasingly popular and sophisticated in recent years. Sometimes it's also stained, and it can be made to look similar to stone, tile or other materials. Damage Concrete can also show superficial/cosmetic surface damage through a process known as "spalling", which occurs when water absorbes beneath the surface and freezes. As the freezing water expands, it pushes on the top surface of the concrete, causing it to "pop" off, creating surface flaking. Spalling can also be caused as steel rebar within the concrete begins to rust and deteriorate -- the expansion in volume caused by the rusting will put pressure on the surface and cause it to pop off. One final way that spalling can occur is when de-icer salt collects deep in the pores of concrete and recrystalizes -- the buildup of these crystals will also create sufficient expansion to lead to salling. Sometimes when slabs of concrete become tilted or uneven, they can be "leveled" instead of replaced. Some companies specialize in the repair of concrete or masonry for residential properties, while others focus on public (municipal), industrial or commercial structures. However, if the unevenness of a concrete slab is due to significiant settlement issues, leveling methods must be carefully considered, as future settlement may occur. New concrete When concrete is first poured it needs to "cure" as it dries. It will dry more evenly and better if it is watered during this time period. The top will absorb the water and set more evenly with the lower area. It absorbs a surprising about of water for the first couple of days. A new driveway can be walked on after about 24-48 hours. If possible, wait about 5 days for heavier items like driving a car on it. Check with your contractor as time periods may vary depending on factors like the weather and thickness. Miscellaneous Concrete can be recycled. Related * cement * stone * exterior * brick * concrete block External links * * American Concrete Institute (ACI) * How to Build and Install a Concrete Countertop on DIY Network Leveling * Maintenance * Concrete Maintenance Basics by Eric Brennan, Yahoo! Contributor Network * AllAboutDriveways.com on Concrete Driveways: Is A Concrete Driveway The Right Choice For Your Home? Commercial sites (since this site is for homes, try to limit the sites to ones that do residential work) * GreeneConcreteLeveling - in northeast Ohio, credited by Wikipedia with coining the term concrete leveling * Concrete Leveling Inc. - Michigan, northwest Ohio * Atlas Concrete Leveling - Ohio, has a photo gallery and high level information about their process * A-1 Concrete Leveling - has franchises with locations around many parts of the continental U.S. Category:Materials Category:construction Category:Demolition